> For the complete documentation index, see [llms.txt](https://dev.guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dev.guardian.hedera.com/guardian/standard-registry/policies/formula-linked-definitions/apis-related-to-formula-linked/update-the-formula-by-its-id.md).

# Update the formula by its ID

**`PUT /api/v1/formulas/{formulaId}`**

Updates the configuration of an existing formula for the specified formula ID.

**Authentication:** Bearer token required (`Authorization: Bearer <token>`)

**Permission:** `Permissions.FORMULAS_FORMULA_CREATE`

***

## Request

### Path Parameters

| Parameter   | Type   | Required | Description                          |
| ----------- | ------ | -------- | ------------------------------------ |
| `formulaId` | string | Yes      | Database ID of the formula to update |

### Request Body

```json
{
  "name": "Updated Carbon Credit Calculator",
  "description": "Updated description",
  "policyId": "63e3e5e8a01b3c001234abcd",
  "config": {}
}
```

| Field         | Type   | Required | Description                                |
| ------------- | ------ | -------- | ------------------------------------------ |
| `name`        | string | No       | Human-readable formula name                |
| `description` | string | No       | Description of the formula's purpose       |
| `policyId`    | string | No       | ID of the policy this formula is linked to |
| `config`      | object | No       | Updated formula expression configuration   |

***

## Response

### Success Response

**Status:** `200 OK`

```json
{
  "id": "63e3e5e8a01b3c001234abcd",
  "uuid": "c4a3b2d1-e5f6-7890-abcd-ef1234567890",
  "name": "Updated Carbon Credit Calculator",
  "description": "Updated description",
  "status": "DRAFT",
  "owner": "did:hedera:testnet:zHcDLGFNymFAJiMBKnpbHDgjvTn6yZnwkPPeFhtJBECH_0.0.4532001",
  "policyId": "63e3e5e8a01b3c001234abcd",
  "config": {}
}
```

### Error Responses

| Status                      | Description                               |
| --------------------------- | ----------------------------------------- |
| `401 Unauthorized`          | Missing or invalid token                  |
| `403 Forbidden`             | Insufficient permissions                  |
| `404 Not Found`             | Formula with the given ID does not exist  |
| `422 Unprocessable Entity`  | `formulaId` parameter is missing or empty |
| `500 Internal Server Error` | Unexpected server failure                 |